7175铝合金热变形行为与热加工图

Hot deformation behaviors and hot processing maps of 7175 aluminum alloy

通过采用热模拟机对7175铝合金进行等温热压缩试验,研究了合金在变形温度为250~480℃、应变速率为0.01~10 s^(-1)范围下的热变形行为。同时,基于Arrhenius双曲正弦本构模型、动态材料模型及Prasad理论建立了7175铝合金的本构方程以及热加工图。结果表明,7175铝合金属于正应变速率敏感材料,并且变形温度和应变速率都对7175铝合金的流变应力有一定的影响,即流变应力随着变形温度的升高而减小,随着应变速率的增大而增大。此外,通过计算获得合金的变形激活能为143.306 kJ·mol^(-1),潜在的危险加工区域主要位于高应变速率区,最佳的热加工区域处于高温低应变速率区,热加工工艺参数范围为450~480℃、0.01~0.17 s^(-1)。

The hot deformation behaviors of 7175 aluminum alloy were investigated by isothermal compression tests at temperatures of 250-480℃and strain rates of 0.01-10 s^(-1) using thermal simulator.Meanwhile,based on the Arrhenius hyperbolic sine constitutive model,dynamic material model and Prasad theory,the constitutive equation and hot processing maps of 7175 aluminum alloy were established.The results show that 7175 aluminum alloy belongs to positive strain rate sensitive material,and both deformation temperature and strain rate have certain effects on the flow stress of 7175 aluminum alloy,that is,the flow stress decreases with the increase of deformation temperature,and increases with the increase of strain rate.In addition,the deformation activation energy of the alloy is 143.306 kJ·mol^(-1),and the potential dangerous working area is mainly located in the high strain rate area,and the optimum hot working area is in the high temperature and low strain rate area.The parameters of hot processing are 450-480℃and 0.01-0.17 s^(-1).